In the far reaches of Western Australia, more than 17,000 people live in indigenous communities spread through 287 townships. Basic services are hard to come by, such as adequate water, wastewater services, and electricity. The Australian Government was faced with how to provide basic electricity to these communities, and in 2006, the Western Australian State Government established Horizon Power, a commercial utility that provides energy services to these remote locations far beyond the reach of Southwest Australia's grid.
Marble Bar and Nullagine are two remote towns with adjacent indigenous communities near the Great Sandy Desert on the far western coast of Australia, about 1,500 km north of Perth. The landscape seems to mimic a scene out of the movie Mad Max—dry, isolated, and barren. With a relatively small population, these communities were bringing in large amounts of diesel—about 786,000 liters per year—by truck. Both of the power stations at Marble Bar and Nullagine were close to 30 years old and in need of replacement. With an abundance of sun, Horizon Power decided not to invest in upgrading the diesel power stations, but instead to embark on an energy journey to bring solar to this remote, diesel-based grid.
Seizing Efficiency First
With 50 percent funding from the Australian Government and 50 percent utility equity, the communities connected 2.24 MW of diesel capacity and 508 kW of solar to the grid, providing 30 percent of their annual electricity generation. They included a flywheel storage system to store the excess energy produced during times of high solar output to reduce dependence on diesel shipments. However, to ensure that they sized their system correctly, they started with determining their electricity demand and understanding how the electricity was being used. The Horizon Power team also provided comprehensive energy audits to ensure that customers understood how to manage their energy consumption.
A disproportionate amount of a household’s income is spent on electricity in Marble Bar and Nullagine. By integrating energy reduction tactics, households were able to reduce their costs more directly. The question of rate impact is often asked when discussing diesel-based grids and especially those in remote locations. In these isolated locations in Western Australia, the government heavily subsidizes the rates for households, so the installation of a solar system that reduces costs of fuel and operations and maintenance may still not translate to an impact at the household level. By leading with energy efficiency though, households were able to see a greater benefit of an energy shift.
Overcoming the Challenges of Working Remote
Through an open tender process, Horizon Power chose SunPower to install the solar array. The construction team had to minimize time on-site due to temperatures as high as 50°C (122°F). Consequently, most components were preassembled off-site. Trackers were assembled in Perth, and then loaded into a cassette arrangement on a truck to ship to the locations. The concrete footings were cast about 2.5 hours away and also driven in to the site. The other major components—such as the inverter housing, switch room, and energy storage systems—were built in larger commercial areas and trucked in as well. With all the preassembly completed ahead of time, the solar array was put together within two days and all the wiring was completed within three to four days. The systems began operation within two weeks with limited operational issues.
This energy story does not come without some lessons learned. When determining their energy storage technology, the team chose a flywheel system. David Edwards, Systems Planning Engineer for Horizon Power, explains: “We learned that flywheels are a really good match for wind, which is available 24 hours a day. But with solar, there are parasitic losses from the flywheel that continue through the night when no solar is available.” If they were to do it again, it is likely that they would use a battery storage system to reduce the losses.
Through their energy transition process in Marble Bar and Nullagine, the Horizon Power team became a leader in how to install systems like this in remote locations, how to manage these complex projects, and how to shift a paradigm within a typical oil- and diesel-based utility. And electricity became more reliable and cleaner for the residents of Marble Bar and Nullagine.
For more on the electricity system at Marble Bar and Nullagine, and nine other renewable microgrids from around the world, download Renewable Microgrids: Profiles from Islands and Remote Communities Across the Globe.
Special thank you to David Edwards from Horizon Power for all his assistance during the creation of the microgrid casebook and, subsequently, this blog post.
Photo Credit: David Edwards and Horizon Power.